论文标题
基于FFA细胞的MUON蓄能环的光学研究
Optics studies of a Muon Accumulator Ring based on FFA cells
论文作者
论文摘要
对于可能的MUON对撞机而言，强烈，高能量和低渗出度亮束的产生很有趣。意大利Istituto Nazionale di Fisica Nuce（INFN）的低发射音加速器（LEMMA）团队正在研究在固定的细小目标上撞击MUON能量的两倍，从高能正电子束上研究了22.5 GEV低启动物束的生产。引理方案提议从多个（$ 10^2 $到$ 10^3 $）正电子束进行MUON积累，以增加使用两个小的累加环通过目标再循环的单个MUON束的种群，每颗蓄能环，一个。在每个正电子束相互作用上，三个梁（$μ^+$和$μ^ - $在22.5 GEV，$ e^+$在Muon Energy时）在目标上共享相同的相位空间，从而在保留的光束散发体内产生新的MUON。我们研究了使用固定场交替梯度（FFA）弧进行累加器的要求和光学设计，以在目标上循环插座。结果，我们实现了一个紧凑的230 m长蓄能器，具有两个相互作用点，$ \ pm5 $％的能量接受度，在目标$β^*_μ= 20 $ cm处的低Twiss beta功能和一个漂移空间2 $ l^*$ 20 cm的20 cm，足以容纳1％的辐射长度$ x_0 $ x_0 $ $ x_0 $。这些光学参数是用类似于FCC或CLIC（例如新磁铁）的磁铁获得的，可以通过新的磁铁设计进一步扩展。当前的MUON积累结果将作为梁组合研究的输入。
The production of an intense, high energy and low emittance muon beam is interesting for a possible muon collider. The Low EMittance Muon Accelerator (LEMMA) team at the Istituto Nazionale di Fisica Nucleare (INFN), in Italy, is studying the production of a 22.5 GeV low emittance muon beam from a high energy positron beam at twice the muon energy impinging on a fixed thin target. The LEMMA scheme proposes to perform the muon accumulation from multiple ($10^2$ to $10^3$) positron bunches to increase the population of a single muon bunch that is recirculated through the target using two small accumulator rings, one per muon species. The three beams ($μ^+$ and $μ^-$ at 22.5 GeV and $e^+$ at twice the muon energy) share the same phase space at the target on every positron bunch interaction, producing new muons inside the preserved beam emittance. We study the requirements and optics design of the accumulator to recirculate the muons over the target using a Fixed Field Alternating Gradient (FFA) arc. As a result, we achieve a compact 230 m long accumulator with two Interaction Points, energy acceptance of $\pm5$ %, low twiss beta function at the target $β^*_μ=20$ cm, and a drift space 2$L^*$ of 20 cm enough to accommodate 1 % of a radiation length $X_0$ for several material options. These optics parameters are obtained with magnets similar to those foreseen for new colliders like FCC or CLIC, and could be extended further with new magnet designs. The current muon accumulation results will serve as input for beam combination studies.
